This application requests funds in partial support of a FASEB Summer Research Conference entitled Gastrointestinal Tract IX: Mechanisms of Disease and Protection to be held July 7 - 12, 2001, Whitefish, Montana. This conference will be the ninth in a series of such conferences. Previous meetings have been distinguished by a remarkable degree of success in accomplishing conference goals, including the discussion of cutting-edge research and the inclusion of outstanding scientists working in areas other than digestive diseases whose insights have opened up new areas of research. Participants at the last meeting voted unanimously that another meeting should be held and elected Dr. Gail Hecht as Chair and Dr. James Anderson as Co-Chair for the 2001 meeting. The overall themes for the meeting arose from input provided by previous participants. The proposed meeting will consist of nine scientific sessions on the following topics (1) Inflammation and innate epithelial defense; (2) Host-pathogen interactions in the gastrointestinal tract; (3) The cytoskeleton in intestinal epithelial biology; (4) Establishment and maintenance of cell polarity (5) Regulation and dysregulation of gastrointestinal epithelial ion transport; (6) Molecular physiology of tight junctions; (7) Cell proliferation and differentiation (8) New insights into gastrointestinal cancer; and (9) Technological advances in epithelial biology. The invited speakers and session chairs are an international group, with 33 from North America, 2 from Europe, and 1 from Asia. The Chair and Co-Chair have made a special effort to invite women, minority and young investigators (assistant professor or below) as speakers or session chairs. The Chair of the meeting is a woman as are 2 session chairs and 6 speakers; there is also one African-American speaker and eleven speakers who qualify as young investigators. Funds are requested in partial support of the travel expenses of invited participants. Other funding will be sought from industry and from the American Digestive Health Foundation. Conferences in this series have played a unique role in furthering research into gastrointestinal health and disease by bringing together basic and clinical scientists and by inspiring the careers of junior investigators. This meeting includes a continuous spectrum of topics from cell to molecular approaches that focus on the major diseases that affect the gastrointestinal tract and mechanisms of protection.